U7T2 – Sex Linkage, Autosomal Linkage and Epistasis

Which Chromosome contains more genes?

Which chromosome carries the sex linked alleles?

How can you tell from a pedigree (family tree) that a trait is sex linked?

Which type of allele tends to be sex linked?

Why are women far less likely to show sex linked disorders?

What would be the genotype for a man with colour-blindness (b)?

Which sex is the carrier of sex lined genes?

Being colour blind is a sex-linked disorder. What is the probability of an unaffected male having a colour- blind child with a heterozygous female?

What is the probability of a colour- blind father and a homozygous dominant female having a colour blind child?

What is an autosome?

If two genes are on the same chromosome, how do we say they are linked?

How can you tell if two alleles are autosomally linked?

In hamsters two genes are autosomally linked : Fur and Eye colour . Where Ginger fur = G, and White fur =g. Black eyes = B and red eyes = b. In a cross between a homozygous recessive male for both traits and a heterozygous female for both traits , what would be the expected ratio of Ginger & Black eye, White and Black eye, ginger and red eye and white with red eyes?

The actual ratio of phenotypes after several matings between the above two hamsters was more similar to 6:1:1:6. How are the alleles linked?

In the actual ratio of 6:1:1:6, there were more of the ginger and black eyed hamsters and more of the white with red eyed hamsters than expected. Therefore, there are proportionately fewer of the mixed traits (Ginger and red eyes and white with black eyes). What process allowed those few mixed trait offspring to occur?

What term describes when a characteristic is controlled by more than one gene, and the expression of one gene will effect the expression of others?

This gene interaction once again alters the phenotype ratio. Which type of Epistatic allele will produce a ratio of 9:3:4?

Which statistical test would we use to see if the observed phenotypes are different from the expected phenotypes?